Live fire training is an important part of any firefighting training curriculum. Unfortunately, a number of factors have made conventional live fire training methods unacceptable. For instance, the personal safety of the trainee is compromised. Many firefighters have sustained serious injuries during training fires conducted with abandoned structures. The burning of such structures create fires that are unpredictable and uncontrollable. Moreover, there are serious environmental problems. Live fire training on abandoned structures results in significant air pollution. In fact, many conventional live fire methods have been condemned by government and environmental agencies. In any case, the supply of abandoned structures available to burn for live fire training is fast diminishing because the demand for live fire training is increasing. Firefighters at all levels of experience need access to repeated training situations to keep their skills sharp.
Fortunately, a more effective live fire training concept has been developed. Gas burners are being used to create a vigorous yellow burning flame. The resulting flame is highly controllable, easily monitored, environmentally correct and easy to reproduce. The controlled burner concept is gaining recognition by the Fire Service as a safe, effective training tool, and the U.S. Navy has installed a number of controlled burner systems for shipboard firefighting training. A handful of municipalities have installed similar burners in their existing burn buildings. These systems utilize natural gas or propane in liquid (LPG) or gaseous states as the source of fuel. The fuel is released into the burner at low pressure and is ignited by inextinguishable pilot heads. The size of the resulting flame is controlled by monitoring valves which regulate the gas flow into the training environment.
A primary problem with controlled burner assemblies for fire training is the incursion of extinguishment agents into sensitive areas of the burner. For instance, if the extinguishing agent reaches the pilot, the unit's reliability or operation will be compromised. One of the main ways that agents such as water cause problems is from unwanted reflection from surrounding surfaces. Larger burner assemblies are attacked with high pressure fire houses in lieu of portable extinguishers, and the reflections can be secondary or even tertiary in nature. The need for reliable performance dictates that these reflections be prevented from reaching the burner pilot.